Building on the 2024 UNECE–ECLAC report Reversing direction in the used clothing crisis, this study explores design options for trade-related technical regulations that promote sustainability in the global trade of used textiles while remaining consistent with World Trade Organization (WTO) rules and other international obligations. In WTO terminology, a technical regulation is a mandatory document that specifies product characteristics or related production methods with which compliance is required, typically established to protect public interests such as health, safety, or the environment. International trade can enable a circular economy for textiles by matching supply and demand for re-wearable clothing. Today, however, the system is distorted: ultra-fast fashion has driven volumes up and quality down; exporting countries struggle to separate rewearable items from waste; and importing countries face environmental, health and enforcement burdens. This study outlines a practical path to correct these distortions by designing technical regulations - grounded in WTO rules and aligned with international standards - that raise the quality of traded used clothing and reduce the flow of textile waste.